Inhibitory versus facilitory interference for finger-tapping to verbal and nonverbal, motor, and sensory tasks

The purpose of the present experiment was to investigate lateralized effects of concurrent verbal and nonverbal tasks on right- and left-hand finger-tapping. In addition to the verbal vs. nonverbal dichotomy, both motor and sensory tasks were used. It was predicted that a verbal motor task (reading aloud) would lead to more inhibitory interference for right-hand tappings than would a sensory verbal task (watching and remembering slides with nonsense syllables). Similarly, it was predicted that a motor nonverbal task (humming a tune) would lead to more left-hand inhibitory interference than would a sensory nonverbal task (watching pairs of spatial patterns). Results showed a predicted lateralized right-hand decrement in finger-tapping during the motor verbal task. However, an increase in left-hand tapping frequency above baseline was observed during both sensory tasks, while no significant difference was observed between the hands for the motor nonverbal task.